Showing papers by "Alan Leviton published in 1999"

Maternal infection, fetal inflammatory response, and brain damage in very low birth weight infants

Abstract: Echolucent images (EL) of cerebral white matter, seen on cranial ultrasonographic scans of very low birth weight newborns, predict motor and cognitive limitations. We tested the hypothesis that markers of maternal and feto-placental infection were associated with risks of both early (diagnosed at a median age of 7 d) and late (median age = 21 d) EL in a multi-center cohort of 1078 infants or =1 after membrane rupture and who had membrane inflammation (adjusted OR not calculable), whereas the association of fetal vasculitis with late EL was seen only in infants born <1 h after membrane rupture (OR = 10.8; p = 0.05). Maternal receipt of antibiotic in the 24 h just before delivery was associated with late EL only if delivery occurred <1 h after membrane rupture (OR = 6.9; p = 0.01). Indicators of maternal infection and of a fetal inflammatory response are strongly and independently associated with EL, particularly late EL.

Brain damage in preterm newborns: might enhancement of developmentally regulated endogenous protection open a door for prevention?

Abstract: We present a two-component model of brain white matter damage in preterm neonates. The insult component comprises infection and hypoxia-ischemia, which are both associated with inflammation-related abnormalities in the white matter. The developmental component comprises at least three factors, ie, immaturity of the ependymal/endothelial, oligodendroglial, and endogenous protection systems. All three factors are likely contributors to an increased vulnerability of the preterm newborn's white matter. In this article, we focus on recent developments in oligodendrocyte biology that support the view of certain cytokines and growth factors as oligotrophins based on their capability to enhance oligodendrocyte development or survival. We suggest that research into networks of developmentally regulated endogenous protectors (such as oligotrophins) is necessary to broaden our perspectives in brain injury prevention in preterm newborns.

Characteristics of cranial ultrasound white-matter echolucencies that predict disability: a review.

Abstract: Cranial ultrasound abnormalities, especially a white-matter echolucency, predict disability (Paneth and PintoMartin 1990, Whitaker et al. 1990, Dammann and Leviton 1997), but with limitations. For example, half of very preterm infants who develop cerebral palsy (CP) do not have any abnormality of the white matter (Pinto-Martin et al. 1995, O’Shea et al. 1998). In addition, echolucencies that predict spastic CP are seldom located with descending fibers from the motor cortex (Rogers et al. 1994). These findings have led to the ‘tip of the iceberg’ hypothesis which postulates that cranial ultrasound scans do not detect the entirety of the white-matter damage (Leviton and Gilles 1996). Correlating ultrasound with magnetic resonance images (Huppi et al. 1996, Battin et al. 1998) might provide the best assessment of the ‘tip of the iceberg’ hypothesis. However, as such studies are presently unavailable, we evaluated the hypothesis by exploring structure–function relations using echolucency as the sonographic indicator of white-matter destruction. We prefer the term echolucency to the diagnosis of cystic periventricular leukomalacia because it is descriptive, does not imply histological characteristics, and because we are not able to link every echolucency to a diagnosis of either periventricular leukomalacia or periventricular hemorrhagic infarction (Kuban 1998) using conventional criteria (Volpe 1989). We evaluated 15 studies that satisfied the following criteria: details about the size, extent or location of the cerebral white-matter echolucencies seen on cranial ultrasound scans, follow-up assessment (i.e. motor, cognitive, behavioral, sensory, and so on) related to echolucency characteristics, and a sample size of at least 10 infants (Calame et al. 1985, Calvert et al. 1986, Graziani et al. 1986, Cooke 1987, Graham et al. 1987, Monset-Couchard et al. 1988, Shortland et al. 1988, Zorzi et al. 1988, Fawer and Calame 1991, Ikonen et al. 1992, de Vries et al. 1993, Ringelberg and van de Bor 1993, Fazzi et al. 1994, Fujimoto et al. 1994, Rogers et al. 1994). The reports varied considerably in the detail about location and size of echolucencies, and performance at the time of follow-up assessment. To maximize comparability we tried to allocate the terms used in each report to a common set of descriptors. The descriptors for echolucencies were frontal, frontal-parietal, parietal, parietal-occipital, occipital, frontal-parietal-occipital, unilateral, bilateral, singular, multiple, small, moderate, and large. The outcome descriptors were any CP diagnosis, diplegia, hemiplegia, quadriplegia, mental retardation (IQ or DQ<70), vision impairment, hearing impairment, and severe behavioral problems. Despite the lack of uniformity among the reviewed studies, we pooled the results from all 15 studies. A total of 1384 infants were followed. Of 373 infants diagnosed with echolucencies, only 59% developed CP. Conversely, CP developed in only 3.0% of the 795 infants who had normal head ultrasound scans.

Clinical Markers of Barotrauma and Oxygen Toxicity and Inter-Hospital Variation in Rates of Chronic Lung Disease Among Surviving Very Low Birth Weight Infants

Abstract: Clinical Markers of Barotrauma and Oxygen Toxicity and Inter-Hospital Variation in Rates of Chronic Lung Disease Among Surviving Very Low Birth Weight Infants